<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
ul{
list-style: none;
}
.header{
width: 1280px;
height: 80px;
background-color: rgb(255, 182, 251);
margin: 0 auto;

}
.middle{
width: 1280px;
height: 400px;
margin: 0 auto;


}
.left{
width: 478px;
height: 400px;
background-color: rgb(249, 255, 191);
float: left;
margin-right:1px ;
}
.left-top{
width: 478px;
height: 80px;
background-color: rgb(183, 255, 255);

text-align: left;
}
.right{
width: 800px;
height: 400px;
background-color:rgb(202, 255, 194);
float: left;
text-align: center;
}
.bottom{
width: 1280px;
height: 80px;
background-color: rgb(153, 180, 255);
margin: 0 auto;
}
</style>
</head>
<body>
<div class="header">主要网页标题</div>
<div class="middle">
<div class="left">
<div class="left-top">
左侧上方标题
</div>
<ul>
<li>菜单</li>
<li>Html</li>
<li>CSS</li>
<li>JavaScript</li>
</ul>
</div>
<div class="right">内容在这里</div>
</div>
<div class="bottom">@好好学习</div>
</body>
</html>